Does Earth need a giant moon for plate tectonics and mineral cycles?

[Jackobear]

I read this notion in the media frequently, and before you write me off as a dimwit, I realize that on Earth today, the moon is a huge mediator regarding Earth's spinning and wobbling and it would totally suck if it decided to leave :) However, regarding the likelihood of life developing on earth, it doesn't seem necessary to me that we need a (relatively) gigantic moon to 'stablize' the Earth's rotation and tilt. I'm pretty convinced from simulations and observations that the moon is the result of a huge impact on Earth and I figure that if it weren't for that impact, we wouldn't be so wobbly in the first place, hence no need for the moon's stabilization. Rotation is pretty important to life on earth, but Mars rotates just fine like ours and seems like it should be the normal thing to happen in a star's nebula.(as nearly all planets rotate the same way as the sun and is predicted by Newtonian simulators) Granted venus and mercury spin very slowly, but isn't it true that tidal locking would be more likely the closer you are to the parent body?

So anyways, yes the moon stabilizes the Earth's tilt...but i think the idea that tilt is a necessary to prod evolution w/ seasons is false, because the amazon is virtually seasonless (besides wet and 'dry' seasons) and its the engine of life. The idea that tidal pools are necessary for early cellular life is completely unproven and hypothetical.

Plate tectonics is the possible killer though...w/o the moon, the crust might stabilize (although supposedly Mars may have had it also at one point). W/o tectonics, wouldn't this disrupt mineral cycles such as sulfur and iron? Eventually it would all erode to the bottom of the oceans right? I suppose you could still have some simple lifeforms, but maybe you need a big moon (or some form of tectonics) to keep mineral cycles going...thats the final reason for this post...is it reasonable to assume that you need plate tectonics in order to cycle elements necessary for complex life as we know it?

Thanks

 

[Carid]

Well no moon would mean no tide worth speaking of. Bang goes a whole lot of evolutionary niches.

 

[Jackobear]

Thats fine, w/o tidal pools i think you could still very easily get multicellular life forms.

 

[Vanadium 50]

This thread needs to focus on facts. "I don't think you need X" is just speculation, ungrounded in science.

 

[Carid]

Thats fine, w/o tidal pools i think you could still very easily get multicellular life forms.

I did not suggest that. I said that you would lose a lot of evolutionary niches. Mangrove swamps, estuaries, and wetlands come to mind.

The moon also plays a role in traditional forms of agriculture. Many peasants still pay more attention to the lunar calendar.

I think Vanadium is correct; unless there is a scientific point to discuss then speculation is fruitless.